Brush-rigging for dynamo-electric machines.



G. DUNN. 4 BRUSH RIGGING FOR DYNAMO ELECTRIC MACHINES.

APPLIUAT ION FILED JAN,2,19GB. 922,107.

Patented May 18, 1909.

Inventor- Gno flan/ 2,

Alla

simple and compact and in which the insula- UNITED STATES PATENT OFFICE.

GA N0 DUNN, OF EAST ORANGE, NEW JERfolfiY, ASSIGNOR. 'lO CEOUKER-WUEELER (.OM l'A NY, OF AMIERE, NEW'JERSEY, A CORPORATION OF NEW JEltSl'lY.

BRUBH-RIGGIN G FOR DYNAMOv-EQECTBJO MAQLIINES.

Specification of Letters Patent,

Patented May 18, 1909.

Application filed January 2, 1908. Serial No. 08,876.

To all whom it may concern:

Be it known that l, GANG DUNN, a citizen of the United States of America, and a resident of East Orange, county of Essex, and State of New Jersey, have invented certain new and useful Improvements in Brush-iii ging for Dynamo-Electric Machines, of whic the following is a specification.

The object of this invention is to produce a mush-rigging of rigid mechanical construction, thereby preventing vibration which is tion is effective. To this end, the brushholder is mounted on a brush-stud which proi'ects from the su porting part, the brushiolder being insu ated from the supporting )art by insulation placed between the brushholdcr and the stud and not between the stud and the supporting part, whereby the stud will be electrically dead, and the connection between the sup orting part and stud, which is subjected to t 1e severest strain of any of the parts forming the brush-rigging, can be made with extreme rigidity.

In the accompanying sheet of drawings which forms a part of this specification, Figure 1 is an end view of the brush-rigging, together with a portion of the commutator. Fig. 2 is aside view of the same. Fig. 3 is a top view with the clamping arts of the gruslbholder broken away on t e line III of igr. 1..

The brush-rigging as illustrated comprises a su poi-tip; part 1 which may be any part of the ramework of the motor or any part capable of being secured. in fixed relation to the motor-framework and utilized for the support of the rest of the brush-rigginf, as, for example, an end-shield such as isil ustrated in Unlted States Patent N 0. 792,762 granted June 20 1905. This shield, at the point where the brush rigging is most conveniently connected, is usually a thin web or arm. It is preforabl thickened somewhat or provided '.with a ow boss at the point where a brush-stud 2 is to be attached. This boss is drilled, and in the embodiment illustrated also tapped to receive the threaded end of the 'brush-stud which is screwed 'tiphtly therein without interposed insulation. Vi hen the stud is screwed in as illustrated, it is unnecessary to face oil the end-shield on the brush side, but only on the opposite side against which a jam nut 3 is screwed. The invention, however, is not limited to this screw-threaded construction, but only to a construction in which the brush-stud issecured thereto directly, that is to say, by a snug metallic fit of any character which will insure rigidity of support for the stud without materially increasing the thickness of the supporting part at the point of attachment and providing a long hole for the stud to pass through or providing large clamping faces, as is required when insulation is interposed, since insulation is only to be obtained in ma terials which have not the strength and rigidity of metal. The stud is conveniently formed of cold rolled steel turned down and threaded at one end and the rest, which pro"- jects, is given any polygonal form which will afford security against rotating to the brushholder clamped thereon or even a circular form. In the form shown this is obtained by cutting or forging flattened faces on round stock to give a shape which is approximately rectangular with rounded corners.

A tube of insulation 4 covers the greater portion of the projecting rectangular end of the stud and preferably extends beyond the. end so as to provide as great a surface distance as possible to reduce the creepagc between. the parts to be insulated from each other. This insulation tube as shown is formed of several turns or layers of wet-ted asbestos paper, and over this a layer of sheliacked Inica board lapping on one side, the whole being baked under pressure, but i t may also be formed of paper or cloth or tape or an cthei similar substance. The hrushho der com )rises a base or saddle 5 and a cap. 6, which form clamping parts engaging the projecting end of the stud over the insulation tube, and a rectangular frame 7 which constitutes a ruide and holder for carbon brushes 8 8. The saddle and frame are separate parts held together in adjustable rcln tion )y screws 0 9 which )ass through slots in the base. The brush-holder is thus formed with split clamping parts which when opened can he slipped over lhc insulation tube and then drawn down on the sides of the stud outside the insulation.

Each brush is engaged and pressed against the commutator by a forked lever 10 formed pf sheet metal. Rivets ll 1.]. in the forks of the lever form truunions at the fulcrum points and rest in pillow-blocks l2 12 which project from one side of the brush-holder rame. A spiral tension spring 13 is stretched with a supportin part,

between an eye on one side of the brushholder frame and a sprin pin 14 which is laid across the forks of the ever. The spring operates to keep the trunnions in place in the allow-blocks as well as to hold the end of the ever against the top of the brush. The lever is formed with a thumb-piece 15 by which it may be drawn back so as to bring the line of strain of the s ring across the center of the fulcrum or on t e other side so that the lever will rest out of action or may be unshipped for conveniently removing and replacing brushes.

What I claim as new and desire to secure by Letters Patent of the United States is 1. In a brush-rigging, the combination 0 aprojecting brushstud one end 0 which is rigidly secured thereto directly, an insulation tube surrounding the 'rojecti part of the brushstud, and a rush-hol er clamped to the sides of the brush-stud outside the insulation, substantially as described.

2. In a brush-rigging, the combination with a supportin part, of a poly onal projecting brush-stu one end of whic is rigidly secured thereto directly, an insulation tube surrounding the projecting part of the brushstud, and a brush-holder clamped to the sides of the brush-stud outside the insulation, substantially as described.

3. In a rush-riggin the combination with a supportin part, 0 a projecting brushstud one end 0 which is rigidly secured thereto directly, an insulation tube su rroundin the rojecting part of the brush-stud, and a me holder with split clam ing parts clamped to the sides of the brus stud outside the insulation, substantially as described.

4. In a brush-riggin the combination with a supporting part, 0 a polygonal projecting brush-stud one end of which is rigidly secured thereto directly, an insulation tube surrounding the projecting part of the brushstud, and a brus -holder with split olampin I parts clamped to the sides of the brush-stu outside the insulation, substantially as described.

Signed b me at East Orange, N. J this th day 0 December, 1907.

GANO DUNN.

Witnesses H. C. Hsmuson, HENRY J. FULLER. 

